Overview
GHK-Cu (glycyl-L-histidyl-L-lysine copper) is a naturally occurring tripeptide that binds copper(II) ions with high affinity. It was first isolated from human plasma by Loren Pickart in 1973. Present in blood at approximately 200 ng/mL at age 20, GHK-Cu levels decline to approximately 80 ng/mL by age 60 — a 60% reduction that correlates with decreased regenerative capacity, slower wound healing, and visible skin aging.
What distinguishes GHK-Cu from every other compound on this site is its evidence base. It has multiple randomized controlled trials, a comprehensive gene expression dataset (modulating over 4,000 human genes), cosmetic regulatory clearance in both the U.S. and EU, commercial availability in consumer products, and a 50-year research history spanning multiple independent laboratories. A 2025 meta-analysis of 7 RCTs (456 total participants) confirmed statistically significant improvements in wrinkle depth.
GHK-Cu represents what the peptide space could look like if compounds went through proper scientific evaluation. It is the benchmark against which other research peptides should be measured.
Dosage & Reconstitution
- Vial strength
- 100 mg
- BAC water added
- 3 mL
- Final concentration
- ~33.3 mg/mL
| Weeks | Dosage | Syringe units (U-100) |
|---|---|---|
| Weeks 1–4 | 1 mg | 3 units0.03 mL |
| Weeks 5–8 | 1.5 mg | 4.5 units0.04 mL |
| Weeks 9–12 | 2 mg | 6 units0.06 mL |
FrequencyOnce daily on five days a week, subcutaneous.
Note
For review — no human injectable dosing exists. Every published human study of GHK-Cu is topical; the subcutaneous week ranges and amounts in the chart follow a circulated research protocol, not the studies cited on this page. The concentration strip above the chart is calculated from the vial and water volume and is correct.
Unverified — no cited human study establishes an injected frequency for GHK-Cu.
Both human studies cited on this page — the post-laser recovery work and the 12-week facial aging study — applied GHK-Cu to skin, so the injected schedule charted here has no human evidence behind it at all and is flagged for review rather than presented as dosing. The route matters more here than for most compounds: GHK-Cu carries copper, and copper delivered under the skin does not clear the way copper applied to the surface does, so a topical safety record says nothing about this chart. Athena lists one strength: a 100 mg vial made up with 3 mL comes to about 33.33 mg/mL, which puts the 1 mg starting amount at 3 units and the 2 mg maintenance amount at 6 units — draws small enough that a unit of measurement error is a large proportional change, though every row sits well inside one 50-unit syringe. The five-days-a-week pattern is part of the same circulated protocol and is not a schedule any trial tested.
What this evidence establishes. Every published human study of GHK-Cu is topical. There is no human injectable dosing for GHK-Cu at all — no dose, no frequency, no safety data by that route. Copper-containing peptides also carry a route-specific concern that topical studies say nothing about, since copper delivered systemically does not clear the way copper applied to skin does.
Sources: Yamada et al., 2025 — post-laser recovery · Pickart & Margolina, 2018 — facial aging (n=71, 12 weeks)
For educational and laboratory research purposes only. It does not provide medical advice, dosing recommendations, or instructions for human or veterinary use. Syringe units assume a U-100 syringe, on which 1 mL is 100 units and a 50-unit syringe holds 0.5 mL.
Mechanism of Action
Gene Modulation
Modulates 4,000+ human genes (31.2% show >50% activity change). Upregulates collagen, elastin, and decorin. Downregulates inflammatory and tissue-destructive genes.
Collagen Synthesis
Stimulates Type I and Type III collagen synthesis. A 2024 RCT showed 28% average collagen density increase over 12 weeks (top quartile: 51%).
Wound Healing
Promotes fibroblast proliferation, keratinocyte migration, and angiogenesis. 2024 multicenter study: 25% faster epithelial recovery post-laser with 30% reduction in IL-1β and TNF-α.
Antioxidant Defense
Activates superoxide dismutase (SOD) and other antioxidant enzymes. Copper delivery to metalloenzymes supports endogenous free radical defense systems.
Hair Growth
A 2022 RCT (n=50) showed 22% increase in hair count at 16 weeks vs. 8% with minoxidil. Upregulates β-catenin and Wnt signaling in hair follicles.
SIRT1 / STAT3 Targets
2024–2025 research identified SIRT1 and STAT3 as primary molecular targets, connecting GHK-Cu to longevity and metabolic regulation pathways beyond skin.
Important caveat on MMP-1: GHK-Cu increases expression of MMP-1 (a collagen-degrading enzyme). At therapeutic concentrations, this facilitates healthy collagen remodeling. At excessive concentrations, elevated MMP-1 may paradoxically accelerate collagen breakdown. More is not better.
Research Timeline
Contraindications & Safety Data
GHK-Cu has the strongest safety profile of any compound on the Athena platform. Pooled data from 2020–2026 (12 studies, n=892) reports mild erythema in 4.2% and pruritus in 2.1%, with no systemic copper overload (serum levels unchanged).
| Condition / Factor | Risk Level | Rationale |
|---|---|---|
| Topical use (cosmetic) | LOW | Well-tolerated across 892 pooled participants. Mild redness (4.2%) and itching (2.1%). No systemic copper elevation. |
| Wilson's disease | HIGH | Genetic copper metabolism disorder. Any exogenous copper source is contraindicated. |
| Copper allergy | HIGH | Direct contact sensitization. Patch test recommended if history of metal allergies. |
| Pregnancy / breastfeeding | MODERATE | No specific safety data in pregnancy for topical GHK-Cu. General caution warranted despite low systemic absorption. |
| Injectable use | MODERATE | Injectable GHK-Cu bypasses the skin barrier. Systemic copper levels, injection site reactions, and sterility become relevant factors. Less safety data than topical. |
| Excessive concentration | MODERATE | Elevated MMP-1 at high concentrations may paradoxically degrade collagen. More is not better. Standard cosmetic concentrations are 0.01–0.1%. |
| Active cancer | MODERATE | Angiogenesis promotion and cell proliferation are theoretical concerns. Topical use at cosmetic concentrations is considered low risk; injectable is higher concern. |
Regulatory Status
FDA (Cosmetic): Permitted in cosmetic formulations without concentration limits under U.S. regulations, provided claims remain non-therapeutic (support, firmness, rejuvenation — not healing, regeneration, or treatment).
EU: Permitted under EU cosmetic regulations. Same non-therapeutic claim restrictions apply.
WADA: Not prohibited. Athletes may use GHK-Cu topically without doping concerns.
What this means: GHK-Cu occupies a unique regulatory position. It is the only compound on the Athena platform that is commercially available in regulated consumer products, with actual clinical trial data supporting its claims, and no WADA prohibition. This is the standard every other research peptide should be measured against.
References (APA 7th Edition)
GHK-Cu Research Knowledge Quiz
Test your understanding of GHK-Cu's clinical evidence, mechanism, and unique regulatory position.